Refactor route manager to use sync.Once for wgInterface access

- Added `toInterface` helper to ensure `wgInterface.ToInterface()` is called once.
- Updated route addition/removal methods to use `toInterface` for efficiency.

client/embed/embed.go

@@ -69,6 +69,8 @@ type Options struct {
 	StatePath string
 	// DisableClientRoutes disables the client routes
 	DisableClientRoutes bool
+	// BlockInbound blocks all inbound connections from peers
+	BlockInbound bool
 }
 
 // validateCredentials checks that exactly one credential type is provided
@@ -137,6 +139,7 @@ func New(opts Options) (*Client, error) {
 		PreSharedKey:        &opts.PreSharedKey,
 		DisableServerRoutes: &t,
 		DisableClientRoutes: &opts.DisableClientRoutes,
+		BlockInbound:        &opts.BlockInbound,
 	}
 	if opts.ConfigPath != "" {
 		config, err = profilemanager.UpdateOrCreateConfig(input)

client/internal/dns/host_darwin.go

@@ -9,8 +9,10 @@ import (
 	"io"
 	"net/netip"
 	"os/exec"
+	"slices"
 	"strconv"
 	"strings"
+	"sync"
 
 	log "github.com/sirupsen/logrus"
 	"golang.org/x/exp/maps"
@@ -38,6 +40,9 @@ const (
 type systemConfigurator struct {
 	createdKeys       map[string]struct{}
 	systemDNSSettings SystemDNSSettings
+
+	mu              sync.RWMutex
+	origNameservers []netip.Addr
 }
 
 func newHostManager() (*systemConfigurator, error) {
@@ -218,6 +223,7 @@ func (s *systemConfigurator) getSystemDNSSettings() (SystemDNSSettings, error) {
 	}
 
 	var dnsSettings SystemDNSSettings
+	var serverAddresses []netip.Addr
 	inSearchDomainsArray := false
 	inServerAddressesArray := false
 
@@ -244,9 +250,12 @@ func (s *systemConfigurator) getSystemDNSSettings() (SystemDNSSettings, error) {
 			dnsSettings.Domains = append(dnsSettings.Domains, searchDomain)
 		} else if inServerAddressesArray {
 			address := strings.Split(line, " : ")[1]
-			if ip, err := netip.ParseAddr(address); err == nil && ip.Is4() {
-				dnsSettings.ServerIP = ip.Unmap()
-				inServerAddressesArray = false // Stop reading after finding the first IPv4 address
+			if ip, err := netip.ParseAddr(address); err == nil && !ip.IsUnspecified() {
+				ip = ip.Unmap()
+				serverAddresses = append(serverAddresses, ip)
+				if !dnsSettings.ServerIP.IsValid() && ip.Is4() {
+					dnsSettings.ServerIP = ip
+				}
 			}
 		}
 	}
@@ -258,9 +267,19 @@ func (s *systemConfigurator) getSystemDNSSettings() (SystemDNSSettings, error) {
 	// default to 53 port
 	dnsSettings.ServerPort = DefaultPort
 
+	s.mu.Lock()
+	s.origNameservers = serverAddresses
+	s.mu.Unlock()
+
 	return dnsSettings, nil
 }
 
+func (s *systemConfigurator) getOriginalNameservers() []netip.Addr {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	return slices.Clone(s.origNameservers)
+}
+
 func (s *systemConfigurator) addSearchDomains(key, domains string, ip netip.Addr, port int) error {
 	err := s.addDNSState(key, domains, ip, port, true)
 	if err != nil {

client/internal/dns/host_darwin_test.go

@@ -109,3 +109,169 @@ func removeTestDNSKey(key string) error {
 	_, err := cmd.CombinedOutput()
 	return err
 }
+
+func TestGetOriginalNameservers(t *testing.T) {
+	configurator := &systemConfigurator{
+		createdKeys: make(map[string]struct{}),
+		origNameservers: []netip.Addr{
+			netip.MustParseAddr("8.8.8.8"),
+			netip.MustParseAddr("1.1.1.1"),
+		},
+	}
+
+	servers := configurator.getOriginalNameservers()
+	assert.Len(t, servers, 2)
+	assert.Equal(t, netip.MustParseAddr("8.8.8.8"), servers[0])
+	assert.Equal(t, netip.MustParseAddr("1.1.1.1"), servers[1])
+}
+
+func TestGetOriginalNameserversFromSystem(t *testing.T) {
+	configurator := &systemConfigurator{
+		createdKeys: make(map[string]struct{}),
+	}
+
+	_, err := configurator.getSystemDNSSettings()
+	require.NoError(t, err)
+
+	servers := configurator.getOriginalNameservers()
+
+	require.NotEmpty(t, servers, "expected at least one DNS server from system configuration")
+
+	for _, server := range servers {
+		assert.True(t, server.IsValid(), "server address should be valid")
+		assert.False(t, server.IsUnspecified(), "server address should not be unspecified")
+	}
+
+	t.Logf("found %d original nameservers: %v", len(servers), servers)
+}
+
+func setupTestConfigurator(t *testing.T) (*systemConfigurator, *statemanager.Manager, func()) {
+	t.Helper()
+
+	tmpDir := t.TempDir()
+	stateFile := filepath.Join(tmpDir, "state.json")
+	sm := statemanager.New(stateFile)
+	sm.RegisterState(&ShutdownState{})
+	sm.Start()
+
+	configurator := &systemConfigurator{
+		createdKeys: make(map[string]struct{}),
+	}
+
+	searchKey := getKeyWithInput(netbirdDNSStateKeyFormat, searchSuffix)
+	matchKey := getKeyWithInput(netbirdDNSStateKeyFormat, matchSuffix)
+	localKey := getKeyWithInput(netbirdDNSStateKeyFormat, localSuffix)
+
+	cleanup := func() {
+		_ = sm.Stop(context.Background())
+		for _, key := range []string{searchKey, matchKey, localKey} {
+			_ = removeTestDNSKey(key)
+		}
+	}
+
+	return configurator, sm, cleanup
+}
+
+func TestOriginalNameserversNoTransition(t *testing.T) {
+	netbirdIP := netip.MustParseAddr("100.64.0.1")
+
+	testCases := []struct {
+		name     string
+		routeAll bool
+	}{
+		{"routeall_false", false},
+		{"routeall_true", true},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			configurator, sm, cleanup := setupTestConfigurator(t)
+			defer cleanup()
+
+			_, err := configurator.getSystemDNSSettings()
+			require.NoError(t, err)
+			initialServers := configurator.getOriginalNameservers()
+			t.Logf("Initial servers: %v", initialServers)
+			require.NotEmpty(t, initialServers)
+
+			for _, srv := range initialServers {
+				require.NotEqual(t, netbirdIP, srv, "initial servers should not contain NetBird IP")
+			}
+
+			config := HostDNSConfig{
+				ServerIP:   netbirdIP,
+				ServerPort: 53,
+				RouteAll:   tc.routeAll,
+				Domains:    []DomainConfig{{Domain: "example.com", MatchOnly: true}},
+			}
+
+			for i := 1; i <= 2; i++ {
+				err = configurator.applyDNSConfig(config, sm)
+				require.NoError(t, err)
+
+				servers := configurator.getOriginalNameservers()
+				t.Logf("After apply %d (RouteAll=%v): %v", i, tc.routeAll, servers)
+				assert.Equal(t, initialServers, servers)
+			}
+		})
+	}
+}
+
+func TestOriginalNameserversRouteAllTransition(t *testing.T) {
+	netbirdIP := netip.MustParseAddr("100.64.0.1")
+
+	testCases := []struct {
+		name         string
+		initialRoute bool
+	}{
+		{"start_with_routeall_false", false},
+		{"start_with_routeall_true", true},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			configurator, sm, cleanup := setupTestConfigurator(t)
+			defer cleanup()
+
+			_, err := configurator.getSystemDNSSettings()
+			require.NoError(t, err)
+			initialServers := configurator.getOriginalNameservers()
+			t.Logf("Initial servers: %v", initialServers)
+			require.NotEmpty(t, initialServers)
+
+			config := HostDNSConfig{
+				ServerIP:   netbirdIP,
+				ServerPort: 53,
+				RouteAll:   tc.initialRoute,
+				Domains:    []DomainConfig{{Domain: "example.com", MatchOnly: true}},
+			}
+
+			// First apply
+			err = configurator.applyDNSConfig(config, sm)
+			require.NoError(t, err)
+			servers := configurator.getOriginalNameservers()
+			t.Logf("After first apply (RouteAll=%v): %v", tc.initialRoute, servers)
+			assert.Equal(t, initialServers, servers)
+
+			// Toggle RouteAll
+			config.RouteAll = !tc.initialRoute
+			err = configurator.applyDNSConfig(config, sm)
+			require.NoError(t, err)
+			servers = configurator.getOriginalNameservers()
+			t.Logf("After toggle (RouteAll=%v): %v", config.RouteAll, servers)
+			assert.Equal(t, initialServers, servers)
+
+			// Toggle back
+			config.RouteAll = tc.initialRoute
+			err = configurator.applyDNSConfig(config, sm)
+			require.NoError(t, err)
+			servers = configurator.getOriginalNameservers()
+			t.Logf("After toggle back (RouteAll=%v): %v", config.RouteAll, servers)
+			assert.Equal(t, initialServers, servers)
+
+			for _, srv := range servers {
+				assert.NotEqual(t, netbirdIP, srv, "servers should not contain NetBird IP")
+			}
+		})
+	}
+}

client/internal/dns/host_windows.go

@@ -42,6 +42,10 @@ const (
 	dnsPolicyConfigConfigOptionsKey     = "ConfigOptions"
 	dnsPolicyConfigConfigOptionsValue   = 0x8
 
+	// NRPT rules cannot handle more than 50 domains per rule.
+	// This is an undocumented Windows limitation.
+	nrptMaxDomainsPerRule = 50
+
 	interfaceConfigPath          = `SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces`
 	interfaceConfigNameServerKey = "NameServer"
 	interfaceConfigSearchListKey = "SearchList"
@@ -239,23 +243,32 @@ func (r *registryConfigurator) addDNSSetupForAll(ip netip.Addr) error {
 func (r *registryConfigurator) addDNSMatchPolicy(domains []string, ip netip.Addr) (int, error) {
 	// if the gpo key is present, we need to put our DNS settings there, otherwise our config might be ignored
 	// see https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-gpnrpt/8cc31cb9-20cb-4140-9e85-3e08703b4745
-	for i, domain := range domains {
-		localPath := fmt.Sprintf("%s-%d", dnsPolicyConfigMatchPath, i)
-		gpoPath := fmt.Sprintf("%s-%d", gpoDnsPolicyConfigMatchPath, i)
 
-		singleDomain := []string{domain}
+	// NRPT rules have an undocumented restriction: each rule can only handle up to 50 domains.
+	// We need to batch domains into chunks and create one NRPT rule per batch.
+	ruleIndex := 0
+	for i := 0; i < len(domains); i += nrptMaxDomainsPerRule {
+		end := i + nrptMaxDomainsPerRule
+		if end > len(domains) {
+			end = len(domains)
+		}
+		batchDomains := domains[i:end]
 
-		if err := r.configureDNSPolicy(localPath, singleDomain, ip); err != nil {
-			return i, fmt.Errorf("configure DNS Local policy for domain %s: %w", domain, err)
+		localPath := fmt.Sprintf("%s-%d", dnsPolicyConfigMatchPath, ruleIndex)
+		gpoPath := fmt.Sprintf("%s-%d", gpoDnsPolicyConfigMatchPath, ruleIndex)
+
+		if err := r.configureDNSPolicy(localPath, batchDomains, ip); err != nil {
+			return ruleIndex, fmt.Errorf("configure DNS Local policy for rule %d: %w", ruleIndex, err)
 		}
 
 		if r.gpo {
-			if err := r.configureDNSPolicy(gpoPath, singleDomain, ip); err != nil {
-				return i, fmt.Errorf("configure gpo DNS policy: %w", err)
+			if err := r.configureDNSPolicy(gpoPath, batchDomains, ip); err != nil {
+				return ruleIndex, fmt.Errorf("configure gpo DNS policy for rule %d: %w", ruleIndex, err)
 			}
 		}
 
-		log.Debugf("added NRPT entry for domain: %s", domain)
+		log.Debugf("added NRPT rule %d with %d domains", ruleIndex, len(batchDomains))
+		ruleIndex++
 	}
 
 	if r.gpo {
@@ -264,8 +277,8 @@ func (r *registryConfigurator) addDNSMatchPolicy(domains []string, ip netip.Addr
 		}
 	}
 
-	log.Infof("added %d separate NRPT entries. Domain list: %s", len(domains), domains)
-	return len(domains), nil
+	log.Infof("added %d NRPT rules for %d domains. Domain list: %s", ruleIndex, len(domains), domains)
+	return ruleIndex, nil
 }
 
 func (r *registryConfigurator) configureDNSPolicy(policyPath string, domains []string, ip netip.Addr) error {

client/internal/dns/host_windows_test.go

@@ -97,6 +97,107 @@ func registryKeyExists(path string) (bool, error) {
 }
 
 func cleanupRegistryKeys(*testing.T) {
-	cfg := &registryConfigurator{nrptEntryCount: 10}
+	// Clean up more entries to account for batching tests with many domains
+	cfg := &registryConfigurator{nrptEntryCount: 20}
 	_ = cfg.removeDNSMatchPolicies()
 }
+
+// TestNRPTDomainBatching verifies that domains are correctly batched into NRPT rules
+// with a maximum of 50 domains per rule (Windows limitation).
+func TestNRPTDomainBatching(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping registry integration test in short mode")
+	}
+
+	defer cleanupRegistryKeys(t)
+	cleanupRegistryKeys(t)
+
+	testIP := netip.MustParseAddr("100.64.0.1")
+
+	// Create a test interface registry key so updateSearchDomains doesn't fail
+	testGUID := "{12345678-1234-1234-1234-123456789ABC}"
+	interfacePath := `SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\` + testGUID
+	testKey, _, err := registry.CreateKey(registry.LOCAL_MACHINE, interfacePath, registry.SET_VALUE)
+	require.NoError(t, err, "Should create test interface registry key")
+	testKey.Close()
+	defer func() {
+		_ = registry.DeleteKey(registry.LOCAL_MACHINE, interfacePath)
+	}()
+
+	cfg := &registryConfigurator{
+		guid: testGUID,
+		gpo:  false,
+	}
+
+	testCases := []struct {
+		name              string
+		domainCount       int
+		expectedRuleCount int
+	}{
+		{
+			name:              "Less than 50 domains (single rule)",
+			domainCount:       30,
+			expectedRuleCount: 1,
+		},
+		{
+			name:              "Exactly 50 domains (single rule)",
+			domainCount:       50,
+			expectedRuleCount: 1,
+		},
+		{
+			name:              "51 domains (two rules)",
+			domainCount:       51,
+			expectedRuleCount: 2,
+		},
+		{
+			name:              "100 domains (two rules)",
+			domainCount:       100,
+			expectedRuleCount: 2,
+		},
+		{
+			name:              "125 domains (three rules: 50+50+25)",
+			domainCount:       125,
+			expectedRuleCount: 3,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Clean up before each subtest
+			cleanupRegistryKeys(t)
+
+			// Generate domains
+			domains := make([]DomainConfig, tc.domainCount)
+			for i := 0; i < tc.domainCount; i++ {
+				domains[i] = DomainConfig{
+					Domain:    fmt.Sprintf("domain%d.com", i+1),
+					MatchOnly: true,
+				}
+			}
+
+			config := HostDNSConfig{
+				ServerIP: testIP,
+				Domains:  domains,
+			}
+
+			err := cfg.applyDNSConfig(config, nil)
+			require.NoError(t, err)
+
+			// Verify that exactly expectedRuleCount rules were created
+			assert.Equal(t, tc.expectedRuleCount, cfg.nrptEntryCount,
+				"Should create %d NRPT rules for %d domains", tc.expectedRuleCount, tc.domainCount)
+
+			// Verify all expected rules exist
+			for i := 0; i < tc.expectedRuleCount; i++ {
+				exists, err := registryKeyExists(fmt.Sprintf("%s-%d", dnsPolicyConfigMatchPath, i))
+				require.NoError(t, err)
+				assert.True(t, exists, "NRPT rule %d should exist", i)
+			}
+
+			// Verify no extra rules were created
+			exists, err := registryKeyExists(fmt.Sprintf("%s-%d", dnsPolicyConfigMatchPath, tc.expectedRuleCount))
+			require.NoError(t, err)
+			assert.False(t, exists, "No NRPT rule should exist at index %d", tc.expectedRuleCount)
+		})
+	}
+}

client/internal/dns/mock_server.go

@@ -84,3 +84,13 @@ func (m *MockServer) UpdateServerConfig(domains dnsconfig.ServerDomains) error {
 func (m *MockServer) PopulateManagementDomain(mgmtURL *url.URL) error {
 	return nil
 }
+
+// BeginBatch mock implementation of BeginBatch from Server interface
+func (m *MockServer) BeginBatch() {
+	// Mock implementation - no-op
+}
+
+// EndBatch mock implementation of EndBatch from Server interface
+func (m *MockServer) EndBatch() {
+	// Mock implementation - no-op
+}

client/internal/dns/server.go

@@ -41,6 +41,8 @@ type IosDnsManager interface {
 type Server interface {
 	RegisterHandler(domains domain.List, handler dns.Handler, priority int)
 	DeregisterHandler(domains domain.List, priority int)
+	BeginBatch()
+	EndBatch()
 	Initialize() error
 	Stop()
 	DnsIP() netip.Addr
@@ -83,6 +85,7 @@ type DefaultServer struct {
 	currentConfigHash  uint64
 	handlerChain       *HandlerChain
 	extraDomains       map[domain.Domain]int
+	batchMode          bool
 
 	mgmtCacheResolver *mgmt.Resolver
 
@@ -230,7 +233,9 @@ func (s *DefaultServer) RegisterHandler(domains domain.List, handler dns.Handler
 		// convert to zone with simple ref counter
 		s.extraDomains[toZone(domain)]++
 	}
-	s.applyHostConfig()
+	if !s.batchMode {
+		s.applyHostConfig()
+	}
 }
 
 func (s *DefaultServer) registerHandler(domains []string, handler dns.Handler, priority int) {
@@ -259,6 +264,28 @@ func (s *DefaultServer) DeregisterHandler(domains domain.List, priority int) {
 			delete(s.extraDomains, zone)
 		}
 	}
+	if !s.batchMode {
+		s.applyHostConfig()
+	}
+}
+
+// BeginBatch starts batch mode for DNS handler registration/deregistration.
+// In batch mode, applyHostConfig() is not called after each handler operation,
+// allowing multiple handlers to be registered/deregistered efficiently.
+// Must be followed by EndBatch() to apply the accumulated changes.
+func (s *DefaultServer) BeginBatch() {
+	s.mux.Lock()
+	defer s.mux.Unlock()
+	log.Infof("DNS batch mode enabled")
+	s.batchMode = true
+}
+
+// EndBatch ends batch mode and applies all accumulated DNS configuration changes.
+func (s *DefaultServer) EndBatch() {
+	s.mux.Lock()
+	defer s.mux.Unlock()
+	log.Infof("DNS batch mode disabled, applying accumulated changes")
+	s.batchMode = false
 	s.applyHostConfig()
 }
 
@@ -508,7 +535,9 @@ func (s *DefaultServer) applyConfiguration(update nbdns.Config) error {
 		s.currentConfig.RouteAll = false
 	}
 
-	s.applyHostConfig()
+	if !s.batchMode {
+		s.applyHostConfig()
+	}
 
 	s.shutdownWg.Add(1)
 	go func() {
@@ -615,7 +644,7 @@ func (s *DefaultServer) applyHostConfig() {
 	s.registerFallback(config)
 }
 
-// registerFallback registers original nameservers as low-priority fallback handlers
+// registerFallback registers original nameservers as low-priority fallback handlers.
 func (s *DefaultServer) registerFallback(config HostDNSConfig) {
 	hostMgrWithNS, ok := s.hostManager.(hostManagerWithOriginalNS)
 	if !ok {
@@ -624,6 +653,7 @@ func (s *DefaultServer) registerFallback(config HostDNSConfig) {
 
 	originalNameservers := hostMgrWithNS.getOriginalNameservers()
 	if len(originalNameservers) == 0 {
+		s.deregisterHandler([]string{nbdns.RootZone}, PriorityFallback)
 		return
 	}
 
@@ -871,7 +901,9 @@ func (s *DefaultServer) upstreamCallbacks(
 			}
 		}
 
-		s.applyHostConfig()
+		if !s.batchMode {
+			s.applyHostConfig()
+		}
 
 		go func() {
 			if err := s.stateManager.PersistState(s.ctx); err != nil {
@@ -906,7 +938,9 @@ func (s *DefaultServer) upstreamCallbacks(
 			s.registerHandler([]string{nbdns.RootZone}, handler, priority)
 		}
 
-		s.applyHostConfig()
+		if !s.batchMode {
+			s.applyHostConfig()
+		}
 
 		s.updateNSState(nsGroup, nil, true)
 	}

client/internal/dns/server_export_test.go

@@ -18,7 +18,12 @@ func TestGetServerDns(t *testing.T) {
 		t.Errorf("invalid dns server instance: %s", err)
 	}
 
-	if srvB != srv {
+	mockSrvB, ok := srvB.(*MockServer)
+	if !ok {
+		t.Errorf("returned server is not a MockServer")
+	}
+
+	if mockSrvB != srv {
 		t.Errorf("mismatch dns instances")
 	}
 }

client/internal/dns/test/mock.go

@@ -8,15 +8,21 @@ import (
 
 type MockResponseWriter struct {
 	WriteMsgFunc func(m *dns.Msg) error
+	lastResponse *dns.Msg
 }
 
 func (rw *MockResponseWriter) WriteMsg(m *dns.Msg) error {
+	rw.lastResponse = m
 	if rw.WriteMsgFunc != nil {
 		return rw.WriteMsgFunc(m)
 	}
 	return nil
 }
 
+func (rw *MockResponseWriter) GetLastResponse() *dns.Msg {
+	return rw.lastResponse
+}
+
 func (rw *MockResponseWriter) LocalAddr() net.Addr       { return nil }
 func (rw *MockResponseWriter) RemoteAddr() net.Addr      { return nil }
 func (rw *MockResponseWriter) Write([]byte) (int, error) { return 0, nil }

client/internal/engine.go

@@ -828,6 +828,10 @@ func (e *Engine) handleAutoUpdateVersion(autoUpdateSettings *mgmProto.AutoUpdate
 }
 
 func (e *Engine) handleSync(update *mgmProto.SyncResponse) error {
+	started := time.Now()
+	defer func() {
+		log.Infof("sync finished in %s", time.Since(started))
+	}()
 	e.syncMsgMux.Lock()
 	defer e.syncMsgMux.Unlock()
 

client/internal/networkmonitor/monitor.go

@@ -14,6 +14,7 @@ import (
 	"github.com/cenkalti/backoff/v4"
 	log "github.com/sirupsen/logrus"
 
+	"github.com/netbirdio/netbird/client/iface/netstack"
 	"github.com/netbirdio/netbird/client/internal/routemanager/systemops"
 )
 
@@ -37,6 +38,11 @@ func New() *NetworkMonitor {
 
 // Listen begins monitoring network changes. When a change is detected, this function will return without error.
 func (nw *NetworkMonitor) Listen(ctx context.Context) (err error) {
+	if netstack.IsEnabled() {
+		log.Debugf("Network monitor: skipping in netstack mode")
+		return nil
+	}
+
 	nw.mu.Lock()
 	if nw.cancel != nil {
 		nw.mu.Unlock()

client/internal/routemanager/manager.go

@@ -173,12 +173,21 @@ func (m *DefaultManager) setupAndroidRoutes(config ManagerConfig) {
 }
 
 func (m *DefaultManager) setupRefCounters(useNoop bool) {
+	var once sync.Once
+	var wgIface *net.Interface
+	toInterface := func() *net.Interface {
+		once.Do(func() {
+			wgIface = m.wgInterface.ToInterface()
+		})
+		return wgIface
+	}
+
 	m.routeRefCounter = refcounter.New(
 		func(prefix netip.Prefix, _ struct{}) (struct{}, error) {
-			return struct{}{}, m.sysOps.AddVPNRoute(prefix, m.wgInterface.ToInterface())
+			return struct{}{}, m.sysOps.AddVPNRoute(prefix, toInterface())
 		},
 		func(prefix netip.Prefix, _ struct{}) error {
-			return m.sysOps.RemoveVPNRoute(prefix, m.wgInterface.ToInterface())
+			return m.sysOps.RemoveVPNRoute(prefix, toInterface())
 		},
 	)
 
@@ -337,6 +346,13 @@ func (m *DefaultManager) updateSystemRoutes(newRoutes route.HAMap) error {
 	}
 
 	var merr *multierror.Error
+
+	// Begin batch mode to avoid calling applyHostConfig() after each DNS handler operation
+	if m.dnsServer != nil {
+		m.dnsServer.BeginBatch()
+		defer m.dnsServer.EndBatch()
+	}
+
 	for id, handler := range toRemove {
 		if err := handler.RemoveRoute(); err != nil {
 			merr = multierror.Append(merr, fmt.Errorf("remove route %s: %w", handler.String(), err))

client/internal/wg_iface_monitor.go

@@ -9,6 +9,8 @@ import (
 	"time"
 
 	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/iface/netstack"
 )
 
 // WGIfaceMonitor monitors the WireGuard interface lifecycle and restarts the engine
@@ -35,6 +37,11 @@ func (m *WGIfaceMonitor) Start(ctx context.Context, ifaceName string) (shouldRes
 		return false, errors.New("not supported on mobile platforms")
 	}
 
+	if netstack.IsEnabled() {
+		log.Debugf("Interface monitor: skipped in netstack mode")
+		return false, nil
+	}
+
 	if ifaceName == "" {
 		log.Debugf("Interface monitor: empty interface name, skipping monitor")
 		return false, errors.New("empty interface name")